FIELD OF THE INVENTION
This invention relates to oil soluble dispersant additives useful in fuel and lubricating oil compositions, including concentrates containing said additives, and methods for their manufacture and use. The dispersant additives are poly (C.sub.5 -C.sub.9 lactone) modified Mannich base adducts which are prepared from moieties of di- or polyamine, high molecular weight hydrocarbyl-substituted hydroxy aromatic material, aldehyde and C.sub.5 -C.sub.9 lactone. The high molecular weight hydrocarbon group has a number average molecular weight (M.sub.n) of about 700 to about 10,000. The additives will have an average degree of polymerization (DP) of the lactone monomer of about 0.2 to about 100.